Modern Countries Once Ruled by Rome

At its zenith (117 CE under Trajan), the Roman Empire encompassed territory of these present-day nations (wholly or partly):

• Europe: Italy, Vatican City, San Marino, Malta, Spain, Portugal, Andorra, France, Monaco, Switzerland, Liechtenstein, Austria, Slovenia, Croatia, Bosnia & Herzegovina, Montenegro, Albania, North Macedonia, Greece, Bulgaria, Romania, Moldova, Ukraine (SW), Hungary, Slovakia, Czechia (S), Germany (W/S), Belgium, Netherlands, Luxembourg, UK (England/Wales), Gibraltar.
• North Africa: Morocco (N), Algeria, Tunisia, Libya, Egypt.
• Near East: Turkey, Cyprus, Syria, Lebanon, Israel, Palestine, Jordan, Iraq (N), Armenia (briefly), Saudi Arabia (NW), Kuwait (tiny), Iran (briefly, Mesopotamia).

~2.5M sq mi, 50–70M people. The only empire to ring the Mediterranean (Mare Nostrum).